<ul id="myTab" class="nav nav-tabs">
    <li class="active">
        <a data-toggle="tab" href="#webmail">Webmail</a>
    </li>
    <li>
        <a data-toggle="tab" href="#helpdesk">Helpdesk</a>
    </li>
</ul>

<div id="myTabContent" class="tab-content">
    <div id="webmail" class="tab-pane fade active in">
        <?php include "frontend/mod/webmail/index.php"; ?>
    </div>
    <div id="helpdesk" class="tab-pane fade">
        <?php include "frontend/mod/helpdesk/index.php"; ?>
    </div>

</div>